Updated November 2025: This article was originally published on November 1, 2022, and has been fully updated with the latest information on thyroid function testing, provincial medical guidelines, naturopathic and patient-pay options, and current lab costs in BC, Alberta, and Ontario.
This article covers everything you need to know about hypothyroidism. It explains how the thyroid works, the key hormones it produces, common causes of an underactive thyroid, and typical signs and symptoms. It also outlines the options available for having thyroid hormone blood tests done.
The Thyroid Gland
The thyroid is a butterfly-shaped gland located in the middle of the lower front part of the neck. While small, it plays a critical role in regulating metabolism—the process by which the body converts food into energy (2).
When the thyroid is underactive (hypothyroid), metabolism slows. This can affect heart rate, heat production, muscle function, thinking, and information processing (1).
The Two Main Thyroid Hormones – T4 and T3
The thyroid produces two main hormones: thyroxine (T4) and triiodothyronine (T3). About 80–90% of thyroid hormone is T4, and 10–20% is T3, most of which is converted from T4 in body tissues (6). On average, the thyroid produces roughly 85 mcg of T4 and 6.5 mcg of T3 per day—a T4:T3 ratio of about 13:1 (1).
T4 is inactive until converted to T3, the active form. In its free form, thyroxine is called free T4 (fT4), and triiodothyronine is called free T3 (fT3) (1).
T4 and T3 production is regulated by the pituitary gland, which responds to the hypothalamus. The hypothalamus releases Thyrotropin-Releasing Hormone (TRH), prompting the pituitary to release TSH (Thyroid Stimulating Hormone), signaling the thyroid to produce hormones (6).
Hypothyroidism – how it is diagnosed
In Canada and many parts of the U.S., TSH is the standard screening test for thyroid function. If symptoms are present or TSH is high-normal, doctors may also check free T4 (7).
Central hypothyroidism occurs when the hypothalamus or pituitary gland fails to signal the thyroid gland properly. Lab tests reveal low TSH and low free T4 levels, and patients are often treated with thyroid medication, including T3 (1).
Primary hypothyroidism occurs when the thyroid itself is underactive. Diagnosis is based on high TSH with normal or low free T4 (1).
Hypothyroidism – main causes
Hashimoto’s disease is the most common cause of primary hypothyroidism in developed countries. It is an autoimmune disorder producing antibodies against the thyroid, including TPO-ab and TG-ab (3). Diagnosis is based on symptoms and antibody testing (3). Iodine deficiency can also underlie hypothyroidism and is more common in developing countries. In the last 20-30 years, it has been largely reduced through global iodization programs (8). Other causes include thyroid surgery or radioactive iodine treatment for hyperthyroidism (1, 2).
Hypothyroidism – getting tested and diagnosed
Many early symptoms of hypothyroidism are non-specific and may have multiple causes.
In British Columbia, unless a person is of advanced age, has a personal or family history of thyroid or autoimmune disorders, takes medications such as lithium or amiodarone, or grew up in a region where salt was not iodized, TSH testing is only covered by MSP if the person has symptoms listed in Table 1 below (4).
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Table 1: Signs and Symptoms of Hypothyroidism (from [4])
One limitation of the checklist is that it does not include well-documented symptoms such as non-pitting edema in the lower legs, a puffy face, an enlarged tongue (with or without scalloped edges), loss of the outer third of the eyebrows, or pale/blue lips (see downloadable checklist, below).
Even if TSH is tested and comes back in the high-normal range, further testing is not done (4). Some clinicians may manually request free T4, but without checking free T3, the assessment is incomplete (7). In order to have TSH, free T4, and free T3 tests done, the doctor needs to write them on the requisition manually. When I request that a doctor write a requisition for thyroid testing for one of my clients, I provide them with a sample requisition of how these tests need to be written based on the current MSP guidelines.
Without a doctor knowing that their patient has risk factors for hypothyroidism based on family history, or that they grew up in a place where salt was not iodized, or that they have several of the known symptoms for hypothyroidism, diagnostic tests may not be requisitioned unless the person becomes sicker.
Downloadable Checklist of Common Hypothyroid Symptoms
To support a more informed discussion with a healthcare provider, below is the link to a downloadable, fillable checklist of common hypothyroid symptoms, which includes a simple explanation for each. For example, “periorbital edema” is described as “swelling under the eyes.”
Keep in mind that these symptoms are not exclusive to hypothyroidism and may exist with other conditions. Only a doctor can determine if there are enough symptoms to warrant further investigation.
This checklist is not exhaustive and is not intended for self-diagnosis. It is provided to help people who suspect they may have hypothyroid symptoms discuss their concerns with their doctor. Only a licensed medical professional can diagnose and treat hypothyroidism.
As a Dietitian, I liaise with my client’s doctors to request that they be tested based onfamilial risk factors and/or symptoms of hypothyroidism and I also support the dietary side of those diagnosed with hypothyroidism, including ensuring that nutrients of importance in the conversion of inactive thyroid hormone (free T4) to the active form (free T3) are sufficient in the diet or supplemented.
Signs and Symptoms of Hypothyroidism – downloadable and fillable checklist
Thyroid Panel Lab Tests – 3 options to test for hypothyroidism
In Canada, there is no single ‘thyroid panel’ routinely ordered to diagnose or rule out hypothyroidism. Medical doctors (MDs) order thyroid tests based on provincial guidelines, while naturopaths offer thyroid testing on a client-pay basis. Below are some available options for having thyroid hormone blood tests done.
1. Medical Doctor (MD)
Thyroid function tests can be ordered by licensed medical doctors (MDs), including family physicians, general practitioners (GPs), and specialists such as endocrinologists. Testing costs are generally covered by the provincial health plan if the requisition follows provincial guidelines.
In BC, Ontario, and Alberta, the provinces where I am licensed to practice, a requisition must follow provincial guidelines.
In Ontario, thyroid tests that are covered are outlined in the Schedule of Benefits for Laboratory Services (SOB‑LS). The latest version is dated February 14, 2025 (effective March 3, 2025).
In British Columbia, guidelines must conform to the BC Guidelines & Protocols Advisory Committee, Thyroid Function Testing in the Diagnosis and Monitoring of Thyroid Function Disorder, October 24, 2018. In BC, doctors face a challenging situation because MSP may seek reimbursement from them if they deem that the tests were not clinically justified (5).
In Alberta, thyroid testing falls under Alberta Precision Laboratories – Update to thyroid hormone reference intervals and to the progressive TSH algorithm (Lab Bulletin, June 13, 2022).
Most physician-initiated investigations for hypothyroidism start with a TSH test (TSH is a pituitary hormone), partly to rule out central hypothyroidism, which occurs when the hypothalamus or pituitary gland is not functioning properly. If TSH is low, a free T4 test is usually ordered. If free T4 is also low, treatment may include T3-containing medication, other therapies, or referral to an endocrinologist.
If TSH is high (above the upper limit of normal), a free T4 test (the inactive form of thyroid hormone) is typically performed, but a free T3 test for the active form of thyroid hormone is not automatically ordered; but needs to be manually requisitioned..
Decisions about treatment or referral to an endocrinologist depend on whether free T4 (and free T3 if tested) is normal or low, and on how far TSH exceeds the reference range.
Provincial Lab Coverage (British Columbia)
According to the Laboratory Services Outpatient Payment Schedule (Issued October 1, 2015; revised March 31, 2025), MSP pays the following amounts for thyroid testing:
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- TSH: $9.90
- Free T4: $12.12
- Free T3: $9.35
- Thyroperoxidase antibody (TPO-ab): $20.22 (for suspected autoimmune thyroid disease)
- Thyroglobulin antibody (TG-ab): $27.90 (performed as an adjunct for thyroid tumors, cancer, etc.)
- Reverse T3: not covered by MSP
Challenges arise when a person’s TSH is in the high-normal range and/or they have symptoms suggestive of hypothyroidism that are not listed in Table 1 of the Guidelines & Protocols for Thyroid Function Testing (4), see Table 1, above.
In British Columbia, it was previously left to the physician’s discretion to order blood tests based on clinical judgment. Since the Laboratory Services Act (LSA) came into effect on October 1, 2015 (5), the MSP can seek reimbursement from a doctor if the tests ordered are deemed not clinically justified. This creates a challenging situation for physicians.
My Role as a Registered Dietitian
When I provide a client with a Lab Test Request Form to take to their doctor asking for thyroid testing, I include the clinical reason for requesting the tests, including personal and family history of thyroid disorders or other related autoimmune conditions, symptoms consistent with the condition, or growing up in a country where the salt was not iodized. This enables the doctor to review the rationale for requesting the blood tests and assess whether they are warranted.
2. Naturopathic Doctor (ND)
In British Columbia, Ontario, and Alberta, thyroid assessment panels typically require a first visit to a naturopath, then a lab test requisition, followed by a second visit to the naturopath for review of results and recommendations. The naturopath’s services are not covered by provincial health insurance, so clients pay out of pocket. They also pay for the costs of the lab tests. Fees for visits and lab test panels vary by province and by individual practitioner.
Ontario
Fees for visits to a naturopath are regulated by the College of Naturopaths of Ontario and are set per block of time. While the College does not set specific visit fees, its “Standard Fees & Billing” guideline requires naturopaths to publish a fee schedule and ensure fees are fair and ethical.
In practice, initial visits (60–90 minutes) typically cost around $200+, and follow-up visits (45 minutes) cost around $115+, though this varies widely by clinic. During the first visit, the naturopath completes an assessment, decides on the thyroid panel requisition, and the client pays the visit fee plus the cost of the lab tests. The naturopath may purchase the lab tests at a negotiated rate and will bill the client, sometimes with a markup. On the second visit, the naturopath interprets the results. The first and second visits together cost over $300, plus the cost of the tests.
The Enhanced Thyroid Assessment available in Ontario includes TSH, Free Thyroxine (FT4), Free Triiodothyronine (FT3), Reverse T3, Thyroperoxidase Antibody (TPO-ab), and Anti-Thyroglobulin (TG-ab). Naturopathic thyroid panel costs generally range between $90–$110 for the panel alone, plus visit costs.
Alberta
Naturopaths are regulated by the College of Naturopathic Doctors of Alberta (CNDA), but there is no established schedule of visit fees. Costs are determined by the individual naturopath or clinic based on the length of visit, complexity, location, etc.
Initial visits typically start at $325, with follow-up visits ranging $160–$185 for 30-minute appointments.
Thyroid testing costs range from $225–$330+, plus the cost of both visits (~$500).
British Columbia
The BC Naturopathic Association Fee Guidelines provide a benchmark for visit fees, and naturopaths may add mark-ups to supplements or lab tests.
Initial visits range $200–$300, with follow-up visits $110–$210 depending on clinic and visit length.
The cost of thyroid panels ordered by a naturopath in BC is not publicly listed, but typically includes TSH, free T4, free T3, rT3, TPO‑ab, and Tg‑ab (called a “Complete Thyroid Panel”). Cost varies between naturopaths, and many clinics add a lab requisition fee ( $12) on top of the test cost.
Should the results come back out of range, one has the option of having the naturopath prescribe treatment or taking the blood test results to a medical doctor for follow-up and treatment.
3. Patient-Pay
In British Columbia, if a doctor does not want to risk requisitioning lab tests that MSP might later consider not clinically justified and ask them to reimburse, the doctor can indicate on the requisition that certain tests to rule out hypothyroidism are “patient-pay.” The individual then pays for those tests themselves.
The person must have a requisition for the tests, even if it is “patient-pay”. Patients cannot go directly to the lab to request these tests. Furthermore, there is no public patient-pay price list at Lifelabs; costs are disclosed only when the patient arrives with the requisition, and “patient-pay” costs are significantly higher than the MSP rates.
That said, a patient-pay price list does exist for Physicians, Registered Dietitians, Nurse Practitioners, and other healthcare professionals titled British Columbia Private Price List for Commonly Ordered Lab Tests, dated April 2021.
Final Thoughts
Determining whether your symptoms are related to your thyroid and navigating testing options can be challenging. Once diagnosed, moving forward with getting prescribed an optimal dose of thyroid replacement medication and optimizing nutrients essential in thyroid hormone conversion is possible. I hope the information in this article helps you have an informed discussion with your doctor.
If you’d like to learn more about the Hypothyroid Management Package that I offer, please visit the Services tab.
To your good health!
Joy
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References
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Jonklaas J, Bianco AC, Bauer AJ, et al. Guidelines for the treatment of hypothyroidism: prepared by the American Thyroid Association task force on thyroid hormone replacement. Thyroid. 2014 Dec 1;24(12):1670–1751.
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Berkow R, Beers MH, Fletcher AJ. The Merck Manual of Medical Information. Whitehouse Station, N.J.: Merck Research Laboratories; 1997.
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Puszkarz I, Guty E, Stefaniak I, Bonarek A. Role of food and nutrition in pathogenesis and prevention of Hashimoto’s thyroiditis. 2018. https://doi.org/10.5281/zenodo.1320419
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BC Guidelines & Protocols Advisory Committee. Thyroid Function Testing in the Diagnosis and Monitoring of Thyroid Function Disorder. October 24, 2018.
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Laboratory Services Act. Laboratory Service Regulation. October 1, 2015 (last amended September 20, 2020 by B.C. Reg. 263/2020).
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NCBI Bookshelf. Physiology of thyroid hormones. 2023. Available at: https://www.ncbi.nlm.nih.gov/books/NBK499850/
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Canadian Thyroid Association. Thyroid Testing Guidelines. 2023. Available at: https://www.thyroid.ca/thyroid-testing-guidelines/
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World Health Organization. Iodine Deficiency Disorders. 2024. Available at: https://www.who.int/news-room/fact-sheets/detail/iodine-deficiency-disorders
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